Martin Luther King Jr.'s daughter has defended Justin Bieber for using snippets from her father's speeches on his new album cover, revealing the pop star asked for permission to feature the civil rights icon.

Bieber came under fire early on Thursday night as his latest record, Justice, dropped, with critics calling the star "tone deaf" for mixing pop songs with King's words.

In fact, the very first voice listeners heard on the album was one of King's speeches, "Injustice anywhere is a threat to justice everywhere", at the beginning of the track 2 Much.

There's also a nearly two-minute MLK Interlude track in the middle of the record, which leads into a song called Die For You.

Bernice King has offered no commentary on how Bieber used her dad's speeches on the album, but she has confirmed he did ask the MLK Estate for clearance.

She tweets: "Thank you, @justinbieber, for your support, in honor of #Justice, of @TheKingCenter’s work and of our #BeLove campaign, which is a part of our global movement for justice."

Bieber is currently embroiled in a legal dispute with dance duo Justice, who have accused Bieber of stealing their logo for the cover art of Justice.